A direct positive silver halide photographic light-sensitive material is used for copying various photographs. In a photomechanical process, a direct positive silver halide light-sensitive material in many cases is used for printing an original halftone dot image from a positive to a positive or from a negative to a negative in a dot to dot work step. The photographic light-sensitive material used for this dot to dot work step is desirably handled under a safelight. Photographic light-sensitive materials which can be handled under orthochromatic and panchromatic safelights are known; however the working efficiency is reduced when using a safelight having such a wavelength and the cost for photomechanical process is increased. For solving these problems, there has recently been developed a photographic light-sensitive material (hereinafter referred to as a daylight photographic light-sensitive material) capable of being handled even under a safelight of a visible ray (a safelight emitting primarily a ray having a wavelength of 450 nm or longer).
However, a direct positive silver halide photographic light-sensitive material having sufficient resistance to a safelight of a visible ray has not hitherto been developed. As a result, reduction of the maximum density and an unfavorable change of the halftone dot area tend to occur in the photomechanical process.
Furthermore, silver chlorobromide rather than silver chloride, and more particularly silver bromide are preferably used for providing the reversal properties, especially the Dmin of a direct reversal emulsion. As a result, the sensitivity of the emulsion is shifted to a longer wavelength region such that it is necessary to use a large amount of dyes to provide protection under a bright safelight.
Under these circumstances, dyes capable of absorbing a UV ray and a visible ray are added to the hydrophilic colloid layers arranged farther from the support than the light-sensitive silver halide emulsion layers in order to provide protection to a safelight. Where these dyes act as a filter layer, it is necessary that such a filter layer is selectively colored and that the other layers are substantially not colored. Particularly, if the emulsion layers also are substantially colored, the photographic properties of the emulsion layers are adversely affected, and the effect of the filter layer is also reduced. More particularly, under these circumstances, a pre-fogged emulsion exhibits an increased Dmin upon storage over a long period of time, and the spreading and chalking properties in a dot to dot work field and the reduction of an outline type property are also adversely affected.
A known method for solving these problems is to localize an acidic dye having a sulfo group or a carboxyl group in a specific layer with a mordant. Mordants typically used for this purpose include the polymers of ethylenically unsaturated compounds having a dialkylaminoalkyl ester residue as described in British Patent 685,474; the reaction products of polyvinylalkyl ketone and aminoguanidine as described in British Patent 850,281; and vinylpyridine polymers and vinylpyridinium cation polymers as described in U.S. Pat. Nos. 2,548,564, 2,484,430, 3,148,061, and 3,756,814. In these patents, cationic polymer mordants having a secondary or tertiary amino group, a nitrogen-containing heterocyclic group and a quaternary cationic group thereof are used such that the above noted acidic dyes are efficiently mordanted.
In these mordants, the above noted acidic dyes tend to diffuse to other layers, and in order to prevent the diffusion, the use of a large quantity of the mordant has been considered. However, the diffusion is not be completely prevented and also the thickness of the layers containing the mordants is increased, which in turn results in new problems originating therefrom.
Furthermore, in a light-sensitive material for printing plate-making, the procedure of reduction using a reducer is usually carried out. In this technique, a water-soluble iron complex is contained as a reduction cutting agent in the reducer, and the above described cationic mordants electrostatically combine with the iron complex to disadvantageously generate yellow stain.
Furthermore, other known means for fixing the dyes in a specific layer of the photographic light-sensitive material include adding the dyes as a dispersed solid body as disclosed in JP-A-56-12639 (the term "JP-A" as used herein means an unexamined published Japanese patent application), JP-A-55-155350, JP-A-55-155351, JP-A-52-92716, JP-A-59-193447, JP-A-61-198148, JP-A-63-197943, JP-A-63-27838, and JP-A-64-40827, European Patent 0015601B1 and 0276566A1, and International Application Publication 88/04794. However, the effect of this technique on a light-sensitive material containing a pre-fogged emulsion has not been reported in the literature.
Pre-fogged emulsions containing transition metals together with silver chloride or silver chlorobromide are described in JP-A-63-75739, JP-A-63-75738, JP-A-2-20852, JP-A-2-20855, JP-A-2-264938, JP-A-2-275940, and JP-A-2-301746, and European Patent 300631.